CVE-2008-2000 in Safari
Summary
by MITRE
Unspecified vulnerability in Apple Safari 3.1.1 allows remote attackers to cause a denial of service (application crash) via JavaScript code that calls document.write in an infinite loop.
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Analysis
by VulDB Data Team • 08/13/2019
The vulnerability identified as CVE-2008-2000 represents a critical denial of service flaw within Apple Safari version 3.1.1 that demonstrates the dangerous potential of improperly handled JavaScript execution patterns. This issue specifically manifests when malicious JavaScript code attempts to invoke the document.write function in an infinite loop scenario, causing the web browser application to crash and become unresponsive. The vulnerability operates at the application level rather than targeting system-level components, making it particularly concerning for web browser security as it directly impacts user experience and application stability.
From a technical perspective, the flaw stems from inadequate input validation and resource management within Safari's JavaScript engine implementation. When the document.write method is repeatedly called without proper loop termination conditions or resource limits, the browser's memory allocation and execution stack become overwhelmed, leading to application instability and eventual crash. This behavior aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which covers buffer overflow vulnerabilities in heap-based memory structures. The infinite loop mechanism essentially exhausts available system resources through uncontrolled execution paths, causing the browser to terminate its processes and display an error message to users.
The operational impact of this vulnerability extends beyond simple application disruption, as it provides attackers with a reliable method to compromise user browsing sessions and potentially disrupt productivity in environments where Safari is the primary browser. In corporate or institutional settings, such a vulnerability could be exploited to create persistent denial of service conditions that would require manual intervention to resolve. The attack vector is particularly concerning because it requires no specialized privileges or access to system resources beyond the ability to deliver malicious JavaScript content through web pages, making it easily exploitable through phishing campaigns, compromised websites, or malicious advertisements.
Security practitioners should note that this vulnerability exemplifies the importance of implementing proper JavaScript execution limits and resource monitoring within web browser environments. The flaw demonstrates how seemingly benign browser functions can be weaponized when combined with improper resource management. Mitigation strategies should include immediate patching of affected Safari versions to 3.1.2 or later, implementing web application firewalls that can detect and block suspicious JavaScript patterns, and deploying browser security extensions that enforce execution limits. Organizations should also consider implementing user education programs to recognize potentially malicious web content and establish incident response procedures for handling browser-based denial of service attacks. The vulnerability serves as a reminder of the critical need for robust input validation and execution monitoring in web browser implementations, aligning with ATT&CK technique T1499.004 which covers network denial of service attacks through web browser exploitation.